haste-server/lib/document_stores/memcached.js

const memcached = require('memcached');
const winston = require('winston');

class MemcachedDocumentStore {

	// Create a new store with options
	constructor(options){
		this.expire = options.expire;

		const host = options.host || '127.0.0.1';
		const port = options.port || 11211;
		const url = `${host}:${port}`;
		this.connect(url);
	}

	// Create a connection
	connect(url){
		this.client = new memcached(url);

		winston.info(`connecting to memcached on ${url}`);

		this.client.on('failure', function(error){
			winston.info('error connecting to memcached', {error});
		});
	}

	// Save file in a key
	set(key, data, callback, skipExpire){
		this.client.set(key, data, skipExpire ? 0 : this.expire, (error) => {
			callback(!error);
		});
	}

	// Get a file from a key
	get(key, callback, skipExpire){
		this.client.get(key, (error, data) => {
			callback(error ? false : data);

			// Update the key so that the expiration is pushed forward
			if (!skipExpire){
				this.set(key, data, (updateSucceeded) => {
					if (!updateSucceeded){
						winston.error('failed to update expiration on GET', {key});
					}
				}, skipExpire);
			}
		});
	}

}

module.exports = MemcachedDocumentStore;